Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK.
Br J Cancer. 2013 Mar 19;108(5):1133-42. doi: 10.1038/bjc.2013.56. Epub 2013 Feb 28.
Clear cell renal cancer frequently harbours von Hippel-Lindau (VHL) gene mutations, leading to stabilisation of the hypoxia-inducible factors (HIFs) and expression of their target genes. We investigated HIF-1 and HIF-2 in the regulation of microRNA-210 (miR-210), and its clinical relevance in renal tumours.
RCC4 and 786-O renal cancer cell lines transfected with either an empty vector or functional VHL and incubated in normoxia or hypoxia were examined for miR-210 expression. Hypoxia-inducible factor siRNAs were used to examine their regulation of miR-210. Seventy-one clear cell renal tumours were sequenced for VHL mutations. Expression of miR-210, VHL, CA9, ISCU and Ki-67 were determined by immunohistochemistry and qRT-PCR.
In addition to HIF-1 regulating miR-210 in renal cancer, HIF-2 can regulate this microRNA in the absence of HIF-1. MicroRNA-210 is upregulated in renal cancer compared with normal renal cortex tissue. MicroRNA-210 correlates negatively with its gene target ISCU at the protein and mRNA level. MicroRNA-210 correlated with positive outcome variables and negatively with Ki-67.
We provide further evidence of miR-210 activity in vivo, and show that high miR-210 expression is associated with better clinico-pathological prognostic factors.
透明细胞肾细胞癌常携带 von Hippel-Lindau（VHL）基因突变，导致缺氧诱导因子（HIFs）的稳定和其靶基因的表达。我们研究了 HIF-1 和 HIF-2 在 microRNA-210（miR-210）调控中的作用及其在肾肿瘤中的临床意义。
用空载体或功能 VHL 转染 RCC4 和 786-O 肾癌细胞系，并在常氧或低氧条件下孵育，检测 miR-210 的表达。使用缺氧诱导因子 siRNA 检测其对 miR-210 的调控作用。对 71 例透明细胞肾肿瘤进行 VHL 基因突变测序。用免疫组化和 qRT-PCR 检测 miR-210、VHL、CA9、ISCU 和 Ki-67 的表达。
除了 HIF-1 调节肾癌细胞中的 miR-210 外，HIF-2 还可以在没有 HIF-1 的情况下调节这种 microRNA。与正常肾皮质组织相比，肾癌细胞中 miR-210 上调。miR-210 在蛋白和 mRNA 水平上与靶基因 ISCU 呈负相关。miR-210 与阳性预后变量相关，与 Ki-67 呈负相关。
我们提供了 miR-210 体内活性的进一步证据，并表明高 miR-210 表达与更好的临床病理预后因素相关。
